Fifa said on Wednesday its number two Fatma Samoura, the first woman to rise to that rank in football's world governing body, would stand down at the end of the year.
In a statement, Samoura said she wanted "to spend more time with my family" while Fifa President Gianni Infantino hailed the Senegalese as "a trailblazer".
Samoura, who was a United Nations veteran, became the first woman to be named FIFA secretary general and was tasked with its day-to-day running as the body looked to fix its reputation after being embroiled in corruption scandals.
Her predecessor Jerome Valcke was fired in 2016 and banned for ethics violations.
"Fifa today is a better governed, more open, more reliable and more transparent organisation. I will leave FIFA with a high sense of pride and fulfilment.
Upcoming World Cup
"For now, I am fully focused on the preparation and delivery of the upcoming Women's World Cup in Australia and New Zealand," Samoura said.
Samoura, who began her U.N. career with the World Food Programme in 1995 and served as country representative or director in six African countries, was heavily involved in impr oving women's football.
"Fatma was the first woman, and the first African, to be appointed to such an important position at FIFA," FIFA President Gianni Infantino said.
"We respect Fatma's decision and I would like to thank her for such dedication and commitment to football."
Samoura oversaw the restructuring of FIFA which included appointing two deputy secretary generals and creating a new women's football division.
